As we age, changes in our body can affect the way medications are absorbed and utilized. We become more sensitive to medications, and we are more likely to experience increased side effects, drug interactions, and other adverse drug reactions.
For medications to be effective, they have to be absorbed in to the body (usually through the intestine), distributed in the body to where they are needed (usually via the bloodstream), chemically changed or metabolized (often in the liver or kidneys) and then removed from the body (mostly through the urine). The normal aging process can change the way medications are absorbed, metabolized, distributed and removed from the body, causing side effects to become more pronounced. These include:
- Increase in the Percentage of Body Fat – As we age, our bodies have more fat relative to our bones and muscles. Although our weight may remain the same, the percentage of body fat increases. Medications that dissolve in fat may get trapped in your body’s fat cells and remain in your system for a longer period of time.
- Decrease in Body Fluid – As we age, the cells in our body lose some of their water, and they are less able to dissolve water-soluble medications. As a result, some medications may become too concentrated in the body, possibly increasing the medication’s effect.
- Decrease in Digestive System Function – As we age, there are changes in our digestive system that can affect how quickly medications enter our bloodstream. The movements in our stomach slow down, and it takes longer for medications to get into our intestines, where they are later absorbed. Also, our stomachs produce less acid, and it takes longer for some drugs to break down. These changes may cause the action of a medication to be decreased or delayed.
- Decrease in Liver Function – The liver is one of the most important organs in our body for metabolizing or breaking down medications. As we age, the liver gets smaller, blood flow to the liver decreases and the chemicals (enzymes) in the liver that break down medications decline. This can result in medications collecting in the liver, thereby causing unwanted side effects and possible damage to the liver.
- Decrease in Kidney Function – Similar to the liver, changes in our kidney function occur as we age. The kidneys may get smaller, blood flow to the kidneys may decrease and our kidneys may become less effective at eliminating “left-over” medications.
- Decrease in Memory – Memory lapses are common in older adults, and as we age, the risk of Alzheimer’s disease and other types of dementia increases. Memory problems can cause people to forget to take medications, which can lead to poor control of their chronic illnesses.
- Decrease in Vision and Hearing – Visual problems, such as diabetic retinopathy, glaucoma, and cataracts, are common in older adults and cause difficulty in reading labels on prescription medication containers and over-the-counter products. Hearing problems can make it difficult for people to hear instructions from their doctors and pharmacists.
- Decrease in Dexterity – Many older people have arthritis, physical disabilities and nervous system disorders. These conditions can make it difficult to open bottles, pick up small pills or handle medications (eye drops, inhalers for asthma and COPD, and insulin injections).
I also wanted to cite a correction for last week’s article. I had indicated that the Canadian Deprescribing Network endorsed a website called Drugs A to Z when in fact they recommend their own website. For more information on medication safety or the risks associated with certain medications, visit the Canadian Deprescribing Network’s website: www.deprescribingnetwork.ca.
Information in this column is compiled by Shell-Lee Wert- Executive Director of CCSH, 470 Dundas Street East, Unit 63, Belleville, K8N 1G1. Please visit our website at https://ccsh.ca, or email me at firstname.lastname@example.org or check out our CCSH Facebook page, or call 613-969-0130 or 613-396-6591 for information and assistance. CCSH is a proud United Way member agency. Funding in part from the South East Local Health Integration Network